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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.myfaces.shared_orchestra.util;
20  
21  import java.util.Enumeration;
22  
23  /**
24   * Enumeration without elements
25   *
26   * @author Anton Koinov (latest modification by $Author: grantsmith $)
27   * @version $Revision: 472630 $ $Date: 2006-11-08 15:40:03 -0500 (Wed, 08 Nov 2006) $
28   */
29  public final class NullEnumeration implements Enumeration
30  {
31      private static final NullEnumeration s_nullEnumeration = new NullEnumeration();
32  
33      public static final NullEnumeration instance()
34      {
35          return s_nullEnumeration;
36      }
37  
38      public boolean hasMoreElements()
39      {
40          return false;
41      }
42  
43      public Object nextElement()
44      {
45          throw new UnsupportedOperationException("NullEnumeration has no elements");
46      }
47  }